U.S. patent application number 14/254364 was filed with the patent office on 2014-10-23 for imprint apparatus and article manufacturing method.
This patent application is currently assigned to CANON KABUSHIKI KAISHA. The applicant listed for this patent is CANON KABUSHIKI KAISHA, Molecular Imprints, Inc.. Invention is credited to Tsuyoshi Arai, Byung-Jin Choi, Makoto Mizuno, Steven C. Shackleton, Yukio Takabayashi.
Application Number | 20140312532 14/254364 |
Document ID | / |
Family ID | 51728419 |
Filed Date | 2014-10-23 |
United States Patent
Application |
20140312532 |
Kind Code |
A1 |
Mizuno; Makoto ; et
al. |
October 23, 2014 |
IMPRINT APPARATUS AND ARTICLE MANUFACTURING METHOD
Abstract
Provided is an imprint apparatus that imprints a pattern formed
on a mold onto a substrate. The imprint apparatus includes a
substrate holder that holds the substrate and can move in a
direction along the surface of the substrate; a gas supply unit for
supplying a gas into a space between a pattern part of the mold and
the substrate; and a wall part that is disposed so as to enclose
the space that is supplied with gas, wherein at a position opposed
to the substrate and the mold, the wall part faces the substrate
holder or the substrate with a gap therebetween.
Inventors: |
Mizuno; Makoto;
(Utsunomiya-shi, JP) ; Arai; Tsuyoshi;
(Utsunomiya-shi, JP) ; Takabayashi; Yukio;
(Saitama-shi, JP) ; Shackleton; Steven C.;
(Austin, TX) ; Choi; Byung-Jin; (Austin,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA
Molecular Imprints, Inc. |
Tokyo
Austin |
TX |
JP
US |
|
|
Assignee: |
CANON KABUSHIKI KAISHA
Tokyo
TX
Molecular Imprints, Inc.
Austin
|
Family ID: |
51728419 |
Appl. No.: |
14/254364 |
Filed: |
April 16, 2014 |
Current U.S.
Class: |
264/299 ;
425/453 |
Current CPC
Class: |
B29C 43/021 20130101;
B29C 43/203 20130101; B29C 2043/025 20130101; B29L 2011/00
20130101; B29K 2101/00 20130101; B29L 2031/34 20130101; G03F 7/0002
20130101 |
Class at
Publication: |
264/299 ;
425/453 |
International
Class: |
B29C 43/20 20060101
B29C043/20 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 18, 2013 |
JP |
2013-087691 |
Claims
1. An imprint apparatus, which imprints a pattern formed in a mold
onto a substrate, comprising: a substrate holder that holds the
substrate and can move in a direction along the surface of the
substrate; a gas supply unit for supplying a gas into a space
between a pattern part of the mold and the substrate; and a wall
part that is disposed so as to enclose the space that is supplied
with gas, wherein at a position opposed to the substrate and the
mold, the wall part faces the substrate holder or the substrate
with a gap therebetween.
2. The imprint apparatus according to claim 1, comprising a gas
exhaust unit that is disposed outside the wall part and exhausts
gas that flows out through the gap.
3. The imprint apparatus according to claim 1, wherein the gas
supply unit comprises a supply port opposing a space into which gas
is supplied, and the end portion of the wall part is disposed, in a
direction perpendicular to the surface of the substrate, more
toward the side of the substrate holder than the supply port.
4. The imprint apparatus according to claim 1, wherein the end
portion of the wall part is disposed, in a direction perpendicular
to the surface of the substrate, more distant from the substrate
holder than the pattern part of the mold.
5. The imprint apparatus according to claim 1, wherein the gap is 1
mm or less.
6. The imprint apparatus according to claim 1, wherein, in the gap,
the wall part is formed such that the flow rate of the gas from the
gas supply unit increases.
7. The imprint apparatus according to claim 1, wherein the gap of
the wall part is set such that, in the gap, the flow rate of the
gas supplied from the gas supply unit becomes equal to or greater
than the movement speed of the substrate holder.
8. The imprint apparatus according to claim 2, comprising a second
wall part that is disposed so as to enclose a space through which
the gas is exhausted, wherein, at a position opposed to the
substrate and the mold, the second wall part opposes the substrate
holder or the substrate with a gap therebetween.
9. The imprint apparatus according to claim 8, wherein the gap of
the second wall part is set such that, in the gap that is formed by
the second wall part, the flow rate of the exhausted gas toward the
space becomes equal to or greater than the movement speed of the
substrate holder.
10. An article manufacturing method comprising: forming a pattern
of a resin on a substrate by using an imprint apparatus; and
processing the substrate in which the pattern has been formed in
the forming, wherein the imprint apparatus is an imprint apparatus
that imprints a pattern formed in a mold onto the substrate and
comprises: a substrate holder that holds the substrate and can move
in a direction along the surface of the substrate; a gas supply
unit for supplying a gas into a space between a pattern part of the
mold and the substrate; and a wall part that is disposed so as to
enclose the space that is supplied with gas, wherein at a position
opposed to the substrate and the mold, the wall part faces the
substrate holder or the substrate with a gap therebetween.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an imprint apparatus and an
article manufacturing method.
[0003] 2. Description of the Related Art
[0004] The demand for micronization of semiconductor devices and
MEMS and the like is increasing, and in addition to conventional
photolithography technologies, a microfabrication technology in
which an uncured resin on a substrate is molded by using a mold and
a resin pattern is formed on a substrate is gaining attention. This
technology is referred to as "imprint technology", and it can form
a fine structure on the order of several nanometers on a substrate.
One example of an imprint technology is a photo-curing method. In
an imprint apparatus that uses this photo-curing method, first an
ultraviolet light-cured resin (imprint material, photo-cured resin)
is applied to a shot, which is an imprint area on a substrate
(wafer). Next, this resin (photo-cured resin) is molded by using a
mold. In addition, a pattern of the resin is formed on the
substrate by separating the cured resin after the resin has been
cured by irradiating an ultraviolet light.
[0005] In this type of imprint apparatus, when a resin is filled
into a fine contoured portion formed in a mold during the pressing
of the mold and the resin on the substrate, there are cases in
which a resin pattern does not form correctly because of unfilled
portions occurring due to bubbles remaining in the resin. Thus,
conventionally, an imprint apparatus has been proposed that
suppresses the retention of bubbles by filling a gap space
sandwiched between the mold and the substrate (resin) during
pressing with a special gas. Japanese Translation of PCT
International Application Publication No. JP-T-2007-509769
discloses an imprint lithography method that includes a step in
which a gas having a high solubility or high diffusibility is fed
at a position in close proximity to the viscous liquid resin on the
substrate.
[0006] However, as disclosed in Japanese Translation of PCT
International Application Publication No. JP-T-2007-509769, in a
state in which only the gap space between a mold and a substrate is
locally filled with a special gas, ambient air will flow from
outside the gap space into the gap space when the substrate is
moved (scanned) in a direction parallel to the mold. In this
situation, because the effect is obtained in which the retention of
bubbles is restrained by supplying a gas into the gap space, the
gas concentration inside the gap space must, to a certain extent,
be maintained at a high value. However, in this case, raising the
gas concentration up to a high value is difficult due to the inflow
of air. Therefore, in a conventional imprint apparatus, for
example, the supplied amount of gas is large, and not just the
inside of the gap space, but a wide area in the vicinity of the
mold must be filled in advance.
SUMMARY OF THE INVENTION
[0007] The present invention provides an imprint apparatus that is
advantageous for, for example, efficiently suppressing the
occurrence of unfilled portions in a resin pattern.
[0008] According to an aspect of the present invention, an imprint
apparatus that imprints a pattern formed in a mold onto a substrate
is provided that includes a substrate holder that holds the
substrate and can move in a direction along the surface of the
substrate; a gas supply unit for supplying a gas into a space
between a pattern part of the mold and the substrate; and a wall
part that is disposed so as to enclose the space that is supplied
with gas, wherein at a position opposed to the substrate and the
mold, the wall part faces the substrate holder or the substrate
with a gap therebetween.
[0009] Further features of the present invention will become
apparent from the following description of exemplary embodiments
with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a drawing that shows a configuration of an imprint
apparatus according to an embodiment of the present invention.
[0011] FIG. 2 is a drawing that shows the configuration of the
vicinity of the mold.
[0012] FIG. 3 is a drawing for explaining the flow of gas that is
exhausted through a discharging path.
[0013] FIG. 4A is a drawing that shows the state upon start of a
pressing operation.
[0014] FIG. 4B is a drawing that shows the state where a resin is
being cured after the pressing operation.
[0015] FIG. 4C is a drawing that shows the state of the cured resin
after a separation operation.
[0016] FIG. 5 is a drawing that shows a configuration of an imprint
apparatus according to another embodiment of the present
invention.
DESCRIPTION OF THE EMBODIMENTS
[0017] Hereinafter, preferred embodiments of the present invention
will be described with reference to the drawings.
[0018] First, an imprint apparatus according to an embodiment of
the present invention will be explained. FIG. 1 is a schematic
drawing that shows a configuration of an imprint apparatus 1
according to the present embodiment. The imprint apparatus 1 is an
apparatus that is used in the manufacture of devices such as
semiconductor devices as an article. The imprint apparatus 1 molds
an uncured resin on a wafer (on a substrate), which is the treated
substrate, by using a mold (original), and forms a pattern in the
resin on the wafer. Note that in this context, an imprint apparatus
that uses a photo-curing method is exemplified. In addition, in the
figures below, the Z axis is aligned parallel to the optical axis
of the irradiation system that irradiates ultraviolet light onto
the resin on a wafer, and the X axis and the Y axis are aligned so
as to be mutually perpendicular within a plane that is
perpendicular to the Z axis. The imprint apparatus 1 is first
provided with a light irradiation unit 2, a mold holding mechanism
3, a gas supply mechanism 4, a wafer stage 5, a dispenser 6, and a
controller 7.
[0019] The light irradiation unit 2 irradiates the mold 8 with
ultraviolet light 9 during the imprint process. Although not
illustrated, this light irradiation unit 2 includes a light source
and an irradiation optical system that adjusts the ultraviolet
light 9 that has been emitted from this light source to a light
suitable for imprinting, and then irradiates the mold 8. Lamps such
as a mercury lamp can be used as a light source, and the light
source is not particularly limited provided that the light source
emits light that passes through to the mold 8 and has a wavelength
by which the resin described below (ultraviolet light-cured resin)
10 is cured. The irradiation light system can include lenses,
mirrors, an aperture, or a shutter for switching between
irradiation and light shielding. Note that in the present
embodiment, a light irradiation unit 2 is installed in order to use
a photo-curing method, but when using, for example, a heat-curing
method, a heat source unit for curing a heat-cured resin may be
installed instead of the light irradiation unit 2.
[0020] The outer peripheral profile of the mold 8 is polygonal
(advantageously, a rectangular profile or a square profile), and
includes a pattern part 8a by which, for example, a contoured
pattern 3 for a circuit pattern and the like to be transferred is
formed three-dimensionally on the surface opposed to the wafer 11.
Note that although various pattern sizes differ depending on the
article that is the object of manufacture, a pattern of tens of
nanometers in a fine article is also included. In addition, the
material of the mold 8 preferably allows passage of ultraviolet
light 9 and has a low thermal expansion rate. Thus, for example,
silicon can be used. Furthermore, at the surface on which
ultraviolet light 9 is irradiated, the mold 8 may also include a
cavity (recessed portion) that has a flat surface profile that is
circular, and that has a certain depth.
[0021] Although not illustrated, a mold holding mechanism (mold
holding unit) 3 includes a mold chuck that holds the mold 8 and a
mold drive mechanism that holds this mold chuck and moves the mold
8. The mold chuck can hold the mold 8 by pulling the outer
peripheral area of the surface of the mold 8, which is irradiated
by the ultraviolet light 9, by using a vacuum suction force or
static electrical force. For example, in the case in which the mold
chuck holds the mold 8 by a vacuum suction force, the mold chuck is
connected to a vacuum pump that is installed externally, and the
mold chuck switches between attaching and detaching the mold 8 by
turning this vacuum pump ON or OFF. In addition, the mold chuck and
the mold drive mechanism include an open area in the center portion
(inside) such that the ultraviolet light 9 that is irradiated from
the light irradiation unit 2 pass through the mold 8 toward the
wafer 11. The mold drive mechanism moves the mold 8 in each axial
direction such that the pressing and separating between the mold 8
and the resin 10 on the wafer 11 is selectively carried out. For
example, a linear motor or an air cylinder can be used to provide a
drive force in this mold drive mechanism. In addition, in order to
accommodate the high precision positioning of the mold 8, the mold
drive mechanism may be structured by a plurality of drive systems,
such as a coarse movement drive system and a fine movement drive
system. Furthermore, a structure is also possible that includes,
for example, a position adjustment function not only for the Z axis
direction, but also for the X axis direction and the Y axis
direction or a .theta. (rotation around the Z axis) direction, and
a tilt function for correcting the tilt of the mold 8. Note that
although the pressing and separating operations in the imprint
apparatus 1 may also be realized by moving the mold 8 in the Z axis
direction, this may be realized by moving the wafer stage 5 in the
Z axis direction or moving both relative to each other.
[0022] The gas supply mechanism (gas supply unit) 4 supplies a gas
to the space (below, referred to as the "gap space") between the
mold 8 and the wafer 11 during the pressing operation. This is in
order to improve the filling characteristics by reducing the time
during which the resin 10 is filled into the contoured pattern of
the pattern part 8a and by suppressing bubbles from being retained
in the filled resin 10. In addition, in order to improve the mold
separation characteristics in which the separation force is reduced
as much as possible, the gas supply mechanism can supply a gas in
the same manner during the separation operation. FIG. 2 is a
schematic cross-sectional view that shows the configuration at the
periphery of the mold 8, which opposes the surface of the wafer 11.
The gas supply mechanism 4 includes a plurality of blowing units 13
that emit a gas 12 toward the side of the wafer 11 that is mounted
on the wafer stage 5 and a supply unit 14 that is connected to this
blowing unit 13 and controls the supply of the gas 12 while
suitably adjusting the supplied amount of gas 12. Note that from
the viewpoint of filling characteristics and the mold separation
characteristics described above, a gas having superior solubility
and diffusibility in the resin 10, such as helium, carbon dioxide,
nitrogen, hydrogen, xenon, or a compressible gas, are preferable
for a gas 12 that can be used.
[0023] The blowing unit 13 is arranged over the entire periphery of
the outer peripheral area of the mold 8, which is being held, at a
surface facing the wafer stage 5 side of the mold holding mechanism
3 (mold chuck). Note that in this manner, the blowing unit 13 may
be arranged such that a gas 12 is ejected only from the one side of
the periphery of the mold 8 instead of a structure that ejects gas
12 from the entire peripheral side of the mold 8. In addition,
preferably an blowing port (supply port) 13a for the gas 12 that is
formed in the blowing unit 13 has a fixed angle, as shown in FIG.
2, in order to supply gas 12 into the gap space with a high
efficiency during the pressing operation. Furthermore, the surface
of the blowing unit 13 that is opposed to the wafer stage 5 is not
a flat surface having a uniform height, but includes a projecting
portion (wall part) 13b that forms a buffer space 15 at a position
opposed to the mold 8 and the wafer 11 and at the side surface of
the mold 8 in a direction parallel to the surface of the wafer 11.
The buffer space 15 is a space, which is opposed to the blowing
ports 13a, by which a gas 12 is supplied, and is a space that
maintains a gas concentration at a high value by retaining the gas
12 a fixed time. In addition, in order to maintain the gas
concentration with a high efficiency, at part of the projection
portion 13b, the position (height) of the opposed surface 13c of
the end portion that opposes the wafer stage 5 is set such that the
gap with the surface of the wafer 11 on the wafer stage 5 becomes
narrow during pressing. Below, the gap amount (tolerance) between
the opposed surface 13c and the surface of the wafer 11 that is
mounted on the wafer stage 5 will be explained.
[0024] Normally, a plurality of shots is present on a wafer 11, and
the wafer stage 5 repeatedly moves in order to move the shot that
is the treatment object to the pressing position. At this time, the
air that is present at the outside of the blowing unit 13 flows
toward the inside at which the mold 8 is present due to the gas
flow that accompanies the movement of the surface of a wafer 11.
For example, as shown in FIG. 2, it is assumed that the wafer stage
5 moves from the right side to the left side on the page in the X
axis direction. In this case, if no special precautions are taken,
the air that is present at the outside of the blowing unit 13 is
carried along with the gas flow 16, and flows from the gap between
the opposed surface 13c and the surface of the wafer 11 into a
buffer space 15 on the inside of the blowing unit 13. Thus, in the
present embodiment, the gap amount between the opposed surface 13c
and the surface of the wafer 11 is set in conformity with the
supplied amount of the gas 12 that is set for the supply unit 14 so
that the concentration of the gas 12 inside the buffer space 15
does not decrease due to the air that flows in from the outside,
and the concentration is thereby maintained at a high value. For
example, first, preferably the end portion of the projecting
portion 13b is disposed in a direction perpendicular to the surface
of the wafer 11, that is, in a direction opposed to the opposing
surface 13c and the wafer 11, so as to be positioned more toward
the wafer stage 5 side than the blowing ports 13a. In addition,
preferably the end portion of the projecting portion 13b is
similarly disposed in a direction perpendicular to the surface of
the wafer 11 at a position more separated from the wafer stage 5
than the pattern part 8a. Additionally, the gap amount is set such
that the flow rate of the gas 12a that passes under the opposing
surface 13c and flows out to the outside increases more than the
flow rate of the gas 12 that flows out from the blowing ports 13a.
For example, the flow rate of the gas 12a at this time may be
adjusted so as to become equal to or greater than the speed at
which the wafer 11 moves (equal to or greater than the movement
speed of the wafer stage 5). That is, the inflow of external air
into the buffer space 15 can be prevented even if the wafer 11 is
moving by directing the gas 12a, having a flow rate equal to or
greater than that of the air, against the air that may flow into
the buffer space 15 at a speed at most equal to the speed at which
the wafer 11 moves. In relation to this, more specifically,
preferably the gap amount is equal to or less than 1 mm when the
mold 8 and the wafer 11 are closest during pressing. In addition,
the height of the opposing surface 13c in the projecting portion
13b is set in advance so as to enable realizing this gap amount.
Note that the phrase "equal to or greater than the speed at which
the wafer 11 moves" includes the meanings that, depending on the
type of the gas 12, the flow rate of the gas 12 can be suitably
varied depending on the required concentration of the gas 12 and
the leakage concentration that can be tolerated when the gas 12
flows to the outside.
[0025] The wafer 11 is, for example, a single crystal silicon
substrate or a SOI (Silicon on Insulator) substrate, and an
ultraviolet curable resin, i.e., the resin 10, which is molded by
the pattern part 8a formed on the mold 8, is applied on the
treatment surface of the wafer 11.
[0026] The wafer stage (substrate holder) 5 holds the wafer 11 and
implements the alignment of the mold 8 and the resin 10 during the
pressing of the mold 8 and the resin 10 on the wafer 11. Although
not illustrated, this wafer stage 5 includes a wafer chuck that
holds the wafer 11 by a suction force and a stage drive mechanism
that holds this wafer chuck by a mechanical means and can move at
least in a direction along the surface of the wafer 11. Examples of
a drive source that can be used in this stage drive mechanism are a
linear motor and a planar motor. The stage drive mechanism may also
be structured by a plurality of drive systems such as a coarse
drive system and a fine drive system and the like in each of the X
axis and Y axis directions. Furthermore, a structure is also
possible that includes drive systems for position adjustment in the
Z axis direction, a position adjustment function in the .theta.
direction of the wafer 11, and a tilt function for correcting the
tilt of the wafer 11 and the like. In addition, the wafer stage 5
is provided, on the side surface thereof, with a plurality of
reference mirrors (reflecting units) corresponding to each of the
X, Y, Z, .omega.x, .omega.y, and .omega.z directions. In contrast,
the imprint apparatus 1 is provided with a plurality of laser
interferometers (length measurement devices) 18 that measure the
position of the wafer stage 5 by irradiating beams onto these
reference mirrors 17. The laser interferometers 18 measure the
position of the wafer stage 5 in real time, and a controller 7,
described below, executes the positioning control of the wafer 11
(wafer stage 5) based on the measured value at this time. Note that
not only a laser interferometers 18, but, for example, encoders and
the like may be used as the length measuring device. In addition,
in FIG. 1, to facilitate simplification, only one set is
illustrated among each of the plurality of reference mirrors 17 and
laser interferometers 18.
[0027] The dispenser 6 is arranged in proximity to the mold holding
mechanism 3, and resin (uncured resin) 10 is applied on a shot,
which serves as a pattern formation area present on the wafer 11.
Here, this resin 10 is photo-cured resin (imprint material) having
the property of being cured when exposed to ultraviolet light 9,
and is suitably selected depending on various conditions of the
semiconductor device manufacturing steps and the like. In addition,
the amount of the resin 10 that is applied (ejected) from the
dispenser 6 is also suitably determined depending on the desired
thickness of the resin 10 that to be formed on the wafer 11 and the
density of the pattern to be formed and the like.
[0028] The controller 7 can control the operation and adjustment
and the like of each of the components of the imprint apparatus 1.
The controller 7 is configured, for example, by a computer and the
like, is connected via circuits to each of the components of the
imprint apparatus 1, and can execute the control of each of the
components according to a program and the like. In addition to the
operation of the mold holding mechanism 3 and the wafer stage 5,
the controller 7 of the present embodiment controls the gas supply
by the gas supply mechanism 4 and the like. Note that the
controller 7 may be integrally structured (housed in a the same
case) with the other portions of the imprint apparatus 1, or may be
structured as a separate unit (housed in a separate case) from the
other portions of the imprint apparatus 1.
[0029] In addition, the imprint apparatus 1 is provided with a
separating wall (second wall part) for suppressing the diffusion of
the gas 12a, which has been supplied by the gas supply mechanism 4
and flows to the outside by passing through the gap under the
opposing surface 13c, into the apparatus space overall. For
example, when the gas 12 that is supplied from the gas supply
mechanism 4 is helium, helium and air each have different
refractive indexes for light, and thus, when helium penetrates into
the light path 20 between the reference mirrors 17 and the laser
interferometers 18, there is the possibility that measurement error
may occur. Normally, the tolerated concentration of helium that can
be allowed to penetrate into the light path 20 by the laser
interferometers 18 is equal to or less than several ppm. In
addition, also in the case in which a different length measuring
device such as an encoder is used instead of the laser
interferometers 18, the helium cannot be ignored because there are
cases in which irregularities in the concentration of the helium
will influence the high precision measurements. Thus, as shown in
FIG. 1, a separating wall part 19 of the present embodiment
encloses at least the mold 8 and the blowing unit 13 in order to
separate them from the external environment, and in the interior
thereof gas 12a (refer to FIG. 2) that has flowed out from the gap
under the opposing surface 13c is exhausted. In this case, as shown
in FIG. 1, the separating wall part 19 forms an exhaust path 21
that is connected to a vacuum pump (exhaust unit; not illustrated)
and the like that is a negative pressure generating source, and the
gas 12a is exhausted by passing through this exhaust path 21.
[0030] FIG. 3 is a schematic cross-sectional view for explaining
the flow of the gas 12a that has been exhausted by passing through
the exhaust path 21. In order for the vacuum pump to exhaust gas
from the entire space that is enclosed by the separating wall part
19, external air flows, as shown by the arrow 22 in FIG. 3, into
the interior of the separating wall part 19 from the gap between
the end surface (separating wall surface) 19a of the separating
wall part 19 that faces the wafer stage side 5 and the surface of
the wafer 11. The air that has flowed therein is exhausted via the
exhaust path 21 mixed with the gas 12a. In order to realize such
exhaust, preferably the gap amount between the end surface 19a and
the surface of the wafer 11 is set in conjunction with the
discharging flow amount at which the vacuum pump exhausts the gas.
In this case as well, the gap amount may be set such that the flow
rate of the air that flows therein by passing under the end surface
19a becomes equal to or greater than the speed at which the wafer
11 moves. That is, the gas 12a in the separating wall part 19 can
be prevented from flowing out to the outside even when the wafer 11
is moving by directing air, having a flow rate equal to or greater
than that of the gas 12a, against the gas 12a that may flow out of
the separating wall part 19 at a speed at most equal to the speed
at which the wafer 11 moves. In relation to this, more
specifically, preferably the gap amount in this case is equal to or
less than 10 mm when the mold 8 and the wafer 11 are in closest
proximity during pressing. In addition, the installation height of
the end surface 19a of the separating wall part 19 is set in
advance so as to enable realizing this gap amount.
[0031] Furthermore, although not illustrated, the imprint apparatus
1 can include an alignment measurement system that measures the
alignment marks on the wafer 11, a mold conveying mechanism that
conveys a mold 8 from the outside of the apparatus to the inside
thereof, and a substrate conveying mechanism that conveys the wafer
11 from the outside of the apparatus to the inside thereof.
[0032] Next, the imprint processing by the imprint apparatus 1 will
be explained. First, the controller 7 mounts and attaches the wafer
11 to the wafer stage 5 by using a substrate conveying apparatus.
Next, the controller 7 sequentially measures the alignment marks on
the wafer 11 by using an alignment measuring system while suitably
changing the position of the wafer 11 by driving the stage drive
mechanism, and detects the position of the wafer 11 with high
precision. In addition, the controller 7 calculates each of the
transfer coordinates based on the results of this detection, and
forms patterns one by one for each predetermined shot based on the
results of these calculations. As a flow for the pattern formation
on one certain shot, the controller 7 first positions the
application position (a predetermined position of the shot) on the
wafer 11 below the blowing port of the dispenser 6 by using the
stage drive mechanism. Subsequently, the dispenser 6 applies a
resin 10 to the shot on the wafer 11 (the application step). Next,
the controller 7 moves and positions the wafer 11 such that the
shot is positioned at the pressing position directly under the
pattern part 8a by using the stage drive mechanism. Next, after
implementing the position alignment of the pattern part 8a and the
shot, the controller 7 drives the mold drive mechanism and presses
the pattern part 8a onto the resin 10 on the shot (mold pressing
step). Due to this pressing, the resin 10 fills the contoured
pattern of the pattern part 8a. Note that the controller 7 carries
out the determination of the pressing completion by using a load
sensor (not illustrated) that is arranged in the interior of the
mold holding mechanism 3. In this state, the light irradiating unit
2 irradiates ultraviolet light 9 for a predetermined time from the
back surface (upper surface) of the mold 8, which serves as a
curing step, and the resin 10 is cured by the ultraviolet light 9
that has passed through the mold 8. In addition, after the resin 10
has been cured, the controller 7 drives the mold drive mechanism
again, and separates the pattern part 8a from the wafer 11 (mold
separation step). Thereby, a three-dimensional resin pattern
(layer) that conforms to the contoured pattern of the pattern part
8a is formed on the surface of the shot on the wafer 11. The
imprint apparatus 1 can form a plurality of resin patterns on one
wafer 11 by executing such a series of imprint operations a
plurality of times while changing the shot by driving the wafer
stage 5.
[0033] In the mold pressing step described above, when the mold 8
and the resin 10 on the wafer 11 are pressed together, the resin 10
must completely fill the contoured pattern of the pattern part 8a.
This is because when the curing of the resin 10 is implemented in a
state in which bubbles are retained inside the resin 10 that has
been filled into the contoured pattern, the resin pattern formed on
the shot does not attain the desired profile and influences the
article itself, such as a semiconductor device that is finally
manufactured. FIG. 4 is a schematic cross-sectional view for
explaining the imprint operation from the mold pressing step to the
mold separation step. In particular, FIG. 4A shows a state in which
the pressing operation has started, FIG. 4B shows a state in which
the resin 10 is cured after the pressing operation, and FIG. 4C
shows the state after the separation operation. In the mold
pressing step and the curing step, the controller 7 fills the resin
10 over the fine portion of the contoured pattern of the pattern
part 8a by supplying a gas 12 into the gap space between the mold 8
and the wafer 11, as shown in FIG. 4A to FIG. 4C, by using the gas
supply mechanism 4. At this time, in the present embodiment, due to
such a structure, it is possible to maintain the concentration of
the gas 12 that is present in the gap space between the mold 8 and
the shot on the wafer 11 at a high value. In particular, according
to the present embodiment, because there is a buffer space 15 and
the gas 12 in this buffer space 15 can be prevented from thinning
due to the inflow of air from the outside, it is possible to fill a
high concentration gas 12 into the gap space with high efficiency
using a flow rate that is lower than a conventional flow rate.
Furthermore, because the imprint apparatus 1 can recover the gas 12
with high efficiency by providing the separating wall part 19, the
influence on the measured values of, for example, the laser
interferometers 18, that is caused by the diffusion of the gas 12,
can be suppressed as much as possible.
[0034] As explained above, according to the present embodiment, it
is possible to provide an imprint unit that is advantageous on the
point of efficiently suppressing the occurrence of unfilled
portions in a pattern in the resin.
[0035] Note that in the present embodiment, although a projecting
portion that forms a wall part for forming a buffer space 15 is
made a projecting portion that is integrated with the blowing unit
13 for the gas 12, the present invention is not limited thereby.
For example, the projecting portion may be made a member that is
separate from the blowing unit 13 and provided in proximity to the
side surface of the blowing unit 13. In addition, with respect to
the location at which the separating wall part 19 is arranged, as
described above, the invention is not thereby limited in particular
provided that a gas 12a that flows out from the buffer space 15 can
be exhausted without diffusing to the outside. The separating wall
part 19 may be one in which, for example, the form of the structure
that supports the mold holding mechanism 3 itself serves as a
separating wall, and may cover the entire structure described above
as an discharging hood. Furthermore, although the structure of the
imprint apparatus 1 shown in FIG. 1 has been omitted, as shown in
FIG. 5, for example, when the wafer stage 5 has a wafer 11 mounted
thereon, a plate (same surface plate) 30 having a surface height
(an identical height) aligned with the surface height of the wafer
11 may be arranged on the outside periphery thereof. Generally, the
shots are set in proximity to the outer periphery on the surface of
the wafer 11. That is, there are also cases in which the surface of
the wafer 11 is not positioned directly under the blowing unit 13
or directly under the end surface 19a of the separating wall part
19 when imprint processing is carried out on the shots that are
present at the outer peripheral area among the shots on the wafer
11. In such a case, by arranging the plate 30 on the wafer stage 5
as described above, the imprint apparatus 1 exhibits the effects
that have been explained above no matter on which shots on the
wafer 11 the imprint processing is implemented.
(Article Manufacturing Method)
[0036] A method for manufacturing a device (semiconductor
integrated circuit element, liquid crystal display element, or the
like) as an article may include a step of forming a pattern onto a
substrate (wafer, glass plate, film-like substrate, or the like)
using the imprint apparatus described above. Furthermore, the
manufacturing method may include a step of etching the substrate on
which a pattern has been formed. When other articles such as a
patterned medium (storage medium), an optical element, or the like
are manufactured, the manufacturing method may include another step
of processing the substrate on which a pattern has been formed
instead of the etching step. The device manufacturing method of
this embodiment has an advantage, as compared with a conventional
device manufacturing method, in at least one of performance,
quality, productivity and production cost of a device.
[0037] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all such modifications and
equivalent structures and functions.
[0038] This application claims the benefit of Japanese Patent
Application No. 2013-087691 filed on Apr. 18, 2013, which is hereby
incorporated by reference herein in its entirety.
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